Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id v9HGk5UE023755 for ; Tue, 17 Oct 2017 18:46:08 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1e4UtN-0006u9-71 for rs_out_1@blacksheep.org; Tue, 17 Oct 2017 17:38:57 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1e4UtM-0006u0-N9 for rsgb_lf_group@blacksheep.org; Tue, 17 Oct 2017 17:38:56 +0100 Received: from porthos.netcom.co.uk ([217.72.171.73]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1e4UtI-0001Py-TV for rsgb_lf_group@blacksheep.org; Tue, 17 Oct 2017 17:38:55 +0100 X-DKIM-Result: Domain=abelian.org Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=abelian.org ; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:References:Reply-To:To:From:Subject:Sender:Cc: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=3KKrQlt/nlhYa5uwGY1pIf8pLARIA+gwX+BNrThvV3g=; b=VASdSANZmzRq5QhaDOk48VCicH x3UQubGgYHO6n27P1NfIprx3j5NrAVxPKwfvs49W59EWvsgFvaoVRG6mj3ixYB40wwl2n2CoCuJx4 hIw9jSdawxSg9IGs264yEkP4OKxnE654FKd0+Gg+PQDYKxLc83rwr/hBQNptR9aczNQo=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:47110 helo=pn.abelian.org) by porthos.netcom.co.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1e4UtG-0005tD-DH for rsgb_lf_group@blacksheep.org; Tue, 17 Oct 2017 17:38:51 +0100 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id E6A5B4004E7 for ; Tue, 17 Oct 2017 16:38:40 +0000 (UTC) From: Paul Nicholson To: rsgb_lf_group@blacksheep.org References: <15ec7c794b3-bff-66@webjas-vac136.srv.aolmail.net> <59D2BD65.4080909@posteo.de> <59D4B109.27652.1415B4FA@mike.dennison.ntlworld.com> <7737095b-edc9-8b5f-ebf5-2a6b2884d425@abelian.org> <59D7940D.7080102@posteo.de> <59DA4E78.7020804@posteo.de> <25d84b3d-2077-a3dc-426c-3f9b92940205@abelian.org> <59DB730D.4080803@posteo.de> <59DE3B9F.70705@posteo.de> <50b0a7b4-a6e6-398d-ea56-dbe66490d1b8@abelian.org> <59E4A8C0.4020707@posteo.de> <59E4B566.5030006@posteo.de> <59E508C6.7090808@posteo.de> <59E51400.60806@posteo.de> <8d3ab44e-f67c-231d-96d3-a9b78acd4d1a@abelian.org> Message-ID: Date: Tue, 17 Oct 2017 16:38:40 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <8d3ab44e-f67c-231d-96d3-a9b78acd4d1a@abelian.org> Content-Language: en-US X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - porthos.netcom.co.uk X-AntiAbuse: Original Domain - blacksheep.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - abelian.org X-Get-Message-Sender-Via: porthos.netcom.co.uk: authenticated_id: catchall@abelian.org X-Authenticated-Sender: porthos.netcom.co.uk: catchall@abelian.org X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: I ran my homebrew propagation model on the great circle from DK7FC in direction of Todmorden. Here's the received signal for the two frequencies, http://abelian.org/vlf/tmp/171017c.gif [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: c1f72e5acb1277e013f90c915ad7ad68 Subject: Re: VLF: EbNaut on 2 frequencies Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=FROM_ENDS_IN_NUMS autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false I ran my homebrew propagation model on the great circle from DK7FC in direction of Todmorden. Here's the received signal for the two frequencies, http://abelian.org/vlf/tmp/171017c.gif given 200mA current and antenna effective height of 20m. Todmorden is at 881 km and the rxed flux density is 6430 Hz: 0.032fT 6510 Hz: 0.046fT so 6510 is about 3dB stronger than 6430. The model uses the international reference ionosphere https://en.wikipedia.org/wiki/International_Reference_Ionosphere and takes account of date, time and bearing. It is ray tracing ground wave and in this case up to 18 hop sky waves. Actually 12 hops seems enough. -- Paul Nicholson --